MEGAPIE target design and LiSoR experiment - Status Report

MEGAPIE is a joint initiative between PSI, CEA, CNRS, ENEA, FZK, JAERI, SCK/CEN, DOE and KAERI to design, build, operate and explore a liquid lead-bismuth spallation target for 1 MW of beam power, taking advantage of the existing spallation neutron facility SINQ at PSI. After a short overview on the MEGAPIE project this paper will concentrate on the material aspects related to the MEGAPIE liquid lead-bismuth target window. The candidate beam window material is a 9Cr-1MoVNb martensitic steel (T91). The LiSoR experiment, being carried out at PSI, simulates severe operating conditions foreseen for future liquid-metal targets such as MEGAPIE in order to validate the material selection relative to irradiation assisted liquid metal corrosion and embrittlement. T91 specimens under stress will be irradiated by 72 MeV protons in flowing liquid lead-bismuth. The experiment will be carried out at the PSI's proton cyclotron INJ1. The major goal is to investigate whether corrosion and embrittlement could be enhanced or triggered under representative irradiation conditions